Methods and systems for drying lipophilic fluid-containing fabrics

ABSTRACT

Methods and/or systems for reducing the drying time of lipophilic fluid-containing fabric articles are provided.

RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 10/307,744, filed Dec. 2, 2002, which claims priority to U.S.Provisional Application Ser. No. 60/312,406 filed Aug. 15, 2001.

FIELD OF THE INVENTION

The present invention relates methods and/or systems for reducing thedrying time of lipophilic fluid-containing fabric articles.

BACKGROUND OF THE INVENTION

Recently, consumers have demanded more from dry cleaning processes. Thedemands may include the use of solvents with better fabric careprofiles. Further, in order to avoid the cost and effort of utilizing acommercial service provider, and in some cases the associateddissatisfaction, some consumers would prefer to have dry-cleaningmachines in their home. In this respect, the consumer can dry cleanitems as needed without leaving home and without waiting for the drycleaner to return the item.

Conventional dry cleaning apparatuses typically introduce a cleaningfluid that contains little, if any, water. Instead, the predominantfluid is typically a lipophilic fluid, that is, a fluid capable ofdissolving sebum and other “oily” soils. Recently, some lipophilicfluids have been identified as having particularly desirable garmentcare profiles. An example of these lipophilic fluids includes thesiloxane based cleaning fluids. Once introduced into the apparatus, thelipophilic fluid typically co-mingles with the fabric load in order toprovide cleaning benefits. The garments are then dried in the sameapparatus or a separate drying apparatus capable of introducing hot airand tumbling the garments.

While some of these lipophilic fluids are less volatile and hence saferfor in-home use, they also tend to have higher boiling points whichmakes for longer drying times. If a dry cleaning apparatus wasintroduced into consumers' homes, the consumers would naturally expectthe machine to be capable of completing an entire load of clothes,including drying, in about one and one-half hours, much like the aqueousbased laundry cycle. However, due to the higher boiling points, and, insome cases, the flammability of some of the preferred lipophilic fluids,this “dry to dry” time limitation may not be feasible.

Accordingly, the need remains for an effective way to attain a shorterdrying time after a lipophilic fluid based fabric cleaning cycle.

SUMMARY OF THE INVENTION

This need is met by the present invention wherein a method foreffectively attaining a shorter drying time after a lipophilic fluidbased fabric cleaning cycle. In general, the invention utilizes at leastone of several ways to “preheat” the fabrics prior to the drying cyclesuch that no time is wasted heating the fabrics during the drying cycle.

The present invention has two embodiments.

In a first embodiment the present invention provides a method to heatfabrics contacted with a lipophilic fluid to a temperature above ambienttemperature, wherein the method includes at least one step from thegroup of blowing a gas onto said fabrics while spraying a rinse liquoronto and tumbling the fabrics before extraction of the rinse liquorbegins; pre-heating a rinse liquor prior to applying the rinse liquor tothe fabrics; exposing the fabrics to an electromagnetic energy sourcewhile spraying a rinse liquor onto and tumbling the fabrics beforeextraction of the rinse liquor begins wherein the electromagnetic energysource is selected from the group of infrared source, microwave sourceand radio frequency source; and, combinations of these steps.

In a second embodiment the present invention provides a system forheating fabrics contacted with a lipophilic fluid to a temperature aboveambient temperature, the system includes the capability to perform atleast one function selected from the group of blowing a gas onto thefabrics while spraying a rinse liquor onto and tumbling the fabricsbefore extraction of the rinse liquor begins; pre-heating a rinse liquorprior to applying the rinse liquor to the fabrics; and, exposing thefabrics to an electromagnetic energy source while spraying a rinseliquor onto and tumbling the fabrics before extraction of the rinseliquor begins wherein the electromagnetic energy source is selected fromthe group of infrared source microwave source and radio frequencysource.

These and other aspects, features and advantages will become apparent tothose of ordinary skill in the art from a reading of the followingdetailed description and the appended claims. All percentages, ratiosand proportions herein are by weight, unless otherwise specified. Alltemperatures are in degrees Celsius (° C.) unless otherwise specified.All measurements are in SI units unless otherwise specified. Alldocuments, books, articles, and references cited are, in relevant part,incorporated herein by reference.

DETAILED DESCRIPTION OF THE INVENTION DEFINITIONS

The terms “fabrics,” “fabric articles,” and “fabric load” used herein isintended to mean any article or group of articles that is customarilycleaned in a conventional laundry process or in a dry cleaning process.As such the term encompasses articles of clothing, linen, drapery, andclothing accessories. The term also encompasses other items made inwhole or in part of fabric, such as tote bags, furniture covers,tarpaulins and the like.

The term “lipophilic fluid” used herein is intended to mean anynon-aqueous fluid capable of removing sebum, as qualified by the testdescribed herein.

The terms “dry”, “drying”, “dried” as they are used in conjunction withthe phrase “lipophilic fluid-containing fabric article(s)” is intendedto mean that the fabric article is dry to the touch and/or that thefabric article contains an amount of lipophilic fluid that is less thanthe absorptive capacity, preferably less than 75% of the absorptioncapacity, more preferably less than 50% of the absorption capacity, evenmore preferably less than 30% of the absorption capacity of the fabricarticle. The phrase “absorption capacity of a fabric article” as usedherein means the maximum quantity of fluid that can be taken in andretained by a fabric article in its pores and interstices. Absorptioncapacity of a fabric article is measured in accordance with thefollowing Test Protocol for Measuring Absorption Capacity of a FabricArticle.

Test Protocol for Measuring the Absorption Capacity of a Fabric Article

Step 1: Rinse and dry a reservoir or other container into which alipophilic fluid will be added. The reservoir is cleaned to free it fromall extraneous matter, particularly soaps, detergents and wettingagents.

Step 2: Weigh a “dry” fabric article to be tested to obtain the “dry”fabric article's weight.

Step 3: Pour 2 L of a lipophilic fluid at ˜20 C into the reservoir.

Step 4: Place fabric article from Step 2 into the lipophilicfluid-containing reservoir.

Step 5: Agitate the fabric article within the reservoir to ensure no airpockets are left inside the fabric article and it is thoroughly wettedwith the lipophilic fluid.

Step 6: Remove the fabric article from the lipophilic fluid-containingreservoir.

Step 7: Unfold the fabric article, if necessary, so that there is nocontact between same or opposite fabric article surfaces.

Step 8: Let the fabric article from Step 7 drip until the drop frequencydoes not exceed 1 drop/sec.

Step 9: Weigh the “wet” fabric article from Step 8 to obtain the “wet”fabric article's weight.

Step 10: Calculate the amount of lipophilic fluid absorbed for thefabric article using the equation below.FA=(W−D)/D*100where:

-   FA=fluid absorbed, % (i.e., the absorption capacity of the fabric    article in terms of % by dry weight of the fabric article)-   W=wet specimen weight, g-   D=initial specimen weight, g

The term “high vapor pressure co-solvent” is intended to mean aco-solvent that has a vapor pressure greater than the vapor pressure ofa lipophilic fluid. Typically, such co-solvents will have a vaporpressure of at least about 3 mm Hg at 20° C.

Treatment Fluids

Treatment fluids or adjuncts can vary widely and can be used at widelyranging levels. For example, detersive enzymes such as proteases,amylases, cellulases, lipases, and the like as well as bleach catalystsincluding the macrocyclic types having manganese or similar transitionmetals all useful in laundry and cleaning products can be used herein atvery low, or less commonly, higher levels. Adjuncts that are catalytic,for example enzymes, can be used in “forward” or “reverse” modes, adiscovery independently useful from the specific appliances of thepresent invention. For example, a lipolase or other hydrolase may beused, optionally in the presence of alcohols as adjuncts, to convertfatty acids to esters, thereby increasing their solubility in thelipohilic fluid. This is a “reverse” operation, in contrast with thenormal use of this hydrolase in water to convert a less water-solublefatty ester to a more water-soluble material. In any event, any adjunctmust be suitable for use in combination with the present invention.

Some suitable adjuncts include, but are not limited to, builders,surfactants, enzymes, emulsifiers, bleach activators, bleach catalysts,bleach boosters, bleaches, alkalinity sources, antibacterial agents,colorants, perfumes, pro-perfumes, finishing aids, lime soapdispersants, composition malodor control agents, odor neutralizers,polymeric dye transfer inhibiting agents, crystal growth inhibitors,photobleaches, heavy metal ion sequestrants, anti-tarnishing agents,anti-microbial agents, anti-oxidants, anti-redeposition agents, soilrelease polymers, electrolytes, pH modifiers, thickeners, abrasives,divalent or trivalent ions, metal ion salts, enzyme stabilizers,corrosion inhibitors, diamines or polyamines and/or their alkoxylates,suds stabilizing polymers, solvents, process aids, fabric softeningagents, optical brighteners, hydrotropes, suds or foam suppressors, sudsor foam boosters, fabric softeners, antistatic agents, dye fixatives,dye abrasion inhibitors, anti-crocking agents, wrinkle reduction agents,wrinkle resistance agents, fabric-pressing starch, soil releasepolymers, soil repellency agents, sunscreen agents, anti-fade agents,waterproofing agents, stainproofing agents, and mixtures thereof.

The term “surfactant” conventionally refers to materials that aresurface-active either in the water, lipophilic fluid, or the mixture ofthe two. Some illustrative surfactants include nonionic, cationic andsilicone surfactants as used in conventional aqueous detergent systems.Suitable nonionic surfactants include, but are not limited to:

-   -   a) polyethylene oxide condensates of nonyl phenol and myristyl        alcohol, such as in U.S. Pat. No. 4,685,930 Kasprzak; and    -   b) fatty alcohol ethoxylates, R—(OCH₂CH₂)_(a)OH a=1 to 100,        typically 12-40, R=hydrocarbon residue 8 to 20 C atoms,        typically linear alkyl. Examples polyoxyethylene lauryl ether,        with 4 or 23 oxyethylene groups; polyoxyethylene cetyl ether        with 2, 10 or 20 oxyethylene groups; polyoxyethylene stearyl        ether, with 2, 10, 20, 21 or 100 oxyethylene groups;        polyoxyethylene (2), (10) oleyl ether, with 2 or 10 oxyethylene        groups. Commercially available examples include, but are not        limited to: ALFONIC, BRIJ, GENAPOL, NEODOL, SURFONIC, TRYCOL.        See also U.S. Pat. No. 6,013,683 Hill, et al.        Suitable cationic surfactants include, but are not limited to        dialkyldimethylammonium salts having the formula:        R′R″N⁺(CH₃)₂X⁻        Where each R′R″ is independently selected from the group        consisting of 12-30 C atoms or derived from tallow, coconut oil        or soy, X═Cl or Br, Examples include: didodecyldimethylammonium        bromide (DDAB), dihexadecyldimethyl ammonium chloride,        dihexadecyldimethyl ammonium bromide, dioctadecyldimethyl        ammonium chloride, dieicosyldimethyl ammonium chloride,        didocosyldimethyl ammonium chloride, dicoconutdimethyl ammonium        chloride, ditallowdimethyl ammonium bromide (DTAB). Commercially        available examples include, but are not limited to: ADOGEN,        ARQUAD, TOMAH, VARIQUAT. See also U.S. Pat. No. 6,013,683 Hill        et al.

Suitable silicone surfactants include, but are not limited to thepolyalkyleneoxide polysiloxanes having a dimethyl polysiloxanehydrophobic moiety and one or more hydrophilic polyalkylene side chainsand have the general formula:R¹—(CH₃)₂SiO—[(CH₃)₂SiO]_(a)[(CH₃)(R¹)SiO]_(b)—Si(CH₃)₂—R¹wherein a+b are from about 1 to about 50, preferably from about 3 toabout 30 , more preferably from about 10 to about 25, and each R¹ is thesame or different and is selected from the group consisting of methyland a poly(ethyleneoxide/propyleneoxide) copolymer group having thegeneral formula:—(CH₂)_(n)O(C₂H₄O)_(c)(C₃H₆O)_(d)R²with at least one R¹ being a poly(ethyleneoxide/propyleneoxide)copolymer group, and wherein n is 3 or 4, preferably 3; total c (for allpolyalkyleneoxy side groups) has a value of from 1 to about 100,preferably from about 6 to about 100; total d is from 0 to about 14,preferably from 0 to about 3; and more preferably d is 0; total c+d hasa value of from about 5 to about 150, preferably from about 9 to about100 and each R² is the same or different and is selected from the groupconsisting of hydrogen, an alkyl having 1 to 4 carbon atoms, and anacetyl group, preferably hydrogen and methyl group. Examples of thesesurfactants may be found in U.S. Pat. No. 5,705,562 Hill and U.S. Pat.No. 5,707,613 Hill.

Examples of this type of surfactants are the Silwet® surfactants whichare available CK Witco, OSi Division, Danbury, Conn. RepresentativeSilwet surfactants are as follows. Name Average MW Average a + b Averagetotal c L-7608 600 1 9 L-7607 1,000 2 17 L-77 600 1 9 L-7605 6,000 20 99L-7604 4,000 21 53 L-7600 4,000 11 68 L-7657 5,000 20 76 L-7602 3,000 2029

The molecular weight of the polyalkyleneoxy group (R¹) is less than orequal to about 10,000. Preferably, the molecular weight of thepolyalkyleneoxy group is less than or equal to about 8,000, and mostpreferably ranges from about 300 to about 5,000. Thus, the values of cand d can be those numbers which provide molecular weights within theseranges. However, the number of ethyleneoxy units (—C₂H₄O) in thepolyether chain (R¹) must be sufficient to render the polyalkyleneoxidepolysiloxane water dispersible or water soluble. If propyleneoxy groupsare present in the polyalkylenoxy chain, they can be distributedrandomly in the chain or exist as blocks. Preferred Silwet surfactantsare L-7600, L-7602, L-7604, L-7605, L-7657, and mixtures thereof.Besides surface activity, polyalkyleneoxide polysiloxane surfactants canalso provide other benefits, such as antistatic benefits, and softnessto fabrics.

The preparation of polyalkyleneoxide polysiloxanes is well known in theart. Polyalkyleneoxide polysiloxanes of the present invention can beprepared according to the procedure set forth in U.S. Pat. No.3,299,112.

Another suitable silicone surfactant is SF-1488, which is available fromGE silicone fluids.

These and other surfactants suitable for use in combination with thelipophilic fluid as adjuncts are well known in the art, being describedin more detail in Kirk Othmer's Encyclopedia of Chemical Technology, 3rdEd., Vol. 22, pp. 360-379, “Surfactants and Detersive Systems.” Furthersuitable nonionic detergent surfactants are generally disclosed in U.S.Pat. No. 3,929,678, Laughlin et al., issued Dec. 30, 1975, at column 13,line 14 through column 16, line 6.

The adjunct may also be an antistatic agent. Any suitable well-knownantistatic agents used in laundering and dry cleaning art are suitablefor use in the methods and compositions of the present invention.Especially suitable as antistatic agents are the subset of fabricsofteners which are known to provide antistatic benefits. For examplethose fabric softeners which have a fatty acyl group which has an iodinevalue of above 20, such as N,N-di(tallowoyl-oxy-ethyl)-N,N-dimethylammonium methylsulfate. However, it is to be understood that the termantistatic agent is not to be limited to just this subset of fabricsofteners and includes all antistatic agents.

The adjunct may also be an emulsifier. Emulsifiers are well known in thechemical art. Essentially, an emulsifier acts to bring two or moreinsoluble or semi-soluble phases together to create a stable orsemi-stable emulsion. It is preferred in the claimed invention that theemulsifier serves a dual purpose wherein it is capable of acting notonly as an emulsifier but also as a treatment performance booster. Forexample, the emulsifier may also act as a surfactant thereby boostingcleaning performance. Both ordinary emulsifiers andemulsifier/surfactants are commercially available.

Lipophilic Fluid

The lipophilic fluid herein is one having a liquid phase present underoperating conditions of a fabric article treating appliance, in otherwords, during treatment of a fabric article in accordance with thepresent invention. In general such a lipophilic fluid can be fullyliquid at ambient temperature and pressure, can be an easily meltedsolid, e.g., one which becomes liquid at temperatures in the range fromabout 0 deg. C. to about 60 deg. C., or can comprise a mixture of liquidand vapor phases at ambient temperatures and pressures, e.g., at 25 deg.C. and 1 atm. pressure. Thus, the lipophilic fluid is not a compressiblegas such as carbon dioxide.

It is preferred that the lipophilic fluids herein be nonflammable orhave relatively high flash points and/or low VOC (volatile organiccompound) characteristics, these terms having their conventionalmeanings as used in the dry cleaning industry, to equal or, preferably,exceed the characteristics of known conventional dry cleaning fluids.

Moreover, suitable lipophilic fluids herein are readily flowable andnonviscous.

In general, lipophilic fluids herein are required to be fluids capableof at least partially dissolving sebum or body soil as defined in thetest hereinafter. Mixtures of lipophilic fluid are also suitable, andprovided that the requirements of the Lipophilic Fluid Test, asdescribed below, are met, the lipophilic fluid can include any fractionof dry-cleaning solvents, especially newer types including fluorinatedsolvents, or perfluorinated amines. Some perfluorinated amines such asperfluorotributylamines while unsuitable for use as lipophilic fluid maybe present as one of many possible adjuncts present in the lipophilicfluid-containing composition.

Other suitable lipophilic fluids include, but are not limited to, diolsolvent systems e.g., higher diols such as C6- or C8- or higher diols,organosilicone solvents including both cyclic and acyclic types, and thelike, and mixtures thereof.

A preferred group of nonaqueous lipophilic fluids suitable forincorporation as a major component of the compositions of the presentinvention include low-volatility nonfluorinated organics, silicones,especially those other than amino functional silicones, and mixturesthereof. Low volatility nonfluorinated organics include for exampleOLEAN® and other polyol esters, or certain relatively nonvolatilebiodegradable mid-chain branched petroleum fractions.

Another preferred group of nonaqueous lipophilic fluids suitable forincorporation as a major component of the compositions of the presentinvention include, but are not limited to, glycol ethers, for examplepropylene glycol methyl ether, propylene glycol n-propyl ether,propylene glycol t-butyl ether, propylene glycol n-butyl ether,dipropylene glycol methyl ether, dipropylene glycol n-propyl ether,dipropylene glycol t-butyl ether, dipropylene glycol n-butyl ether,tripropylene glycol methyl ether, tripropylene glycol n-propyl ether,tripropylene glycol t-butyl ether, tripropylene glycol n-butyl ether.Suitable silicones for use as a major component, e.g., more than 50%, ofthe composition include cyclopentasiloxanes, sometimes termed “D5”,and/or linear analogs having approximately similar volatility,optionally complemented by other compatible silicones. Suitablesilicones are well known in the literature, see, for example, KirkOthmer's Encyclopedia of Chemical Technology, and are available from anumber of commercial sources, including General Electric, ToshibaSilicone, Bayer, and Dow Corning. Other suitable lipophilic fluids arecommercially available from Procter & Gamble or from Dow Chemical andother suppliers.

Qualification of Lipophilic Fluid and Lipophilic Fluid Test (LF Test)

Any nonaqueous fluid that is both capable of meeting known requirementsfor a dry-cleaning fluid (e.g, flash point etc.) and is capable of atleast partially dissolving sebum, as indicated by the test methoddescribed below, is suitable as a lipophilic fluid herein. As a generalguideline, perfluorobutylamine (Fluorinert FC-43®) on its own (with orwithout adjuncts) is a reference material which by definition isunsuitable as a lipophilic fluid for use herein (it is essentially anonsolvent) while cyclopentasiloxanes have suitable sebum-dissolvingproperties and dissolves sebum.

The following is the method for investigating and qualifying othermaterials, e.g., other low-viscosity, free-flowing silicones, for use asthe lipophilic fluid. The method uses commercially available Crisco®canola oil, oleic acid (95% pure, available from Sigma Aldrich Co.) andsqualene (99% pure, available from J.T. Baker) as model soils for sebum.The test materials should be substantially anhydrous and free from anyadded adjuncts, or other materials during evaluation.

Prepare three vials, each vial will contain one type of lipophilic soil.Place 1.0 g of canola oil in the first; in a second vial place 1.0 g ofthe oleic acid (95%), and in a third and final vial place 1.0 g of thesqualene (99.9%). To each vial add 1 g of the fluid to be tested forlipophilicity. Separately mix at room temperature and pressure each vialcontaining the lipophilic soil and the fluid to be tested for 20 secondson a standard vortex mixer at maximum setting. Place vials on the benchand allow to settle for 15 minutes at room temperature and pressure. If,upon standing, a clear single phase is formed in any of the vialscontaining lipophilic soils, then the nonaqueous fluid qualifies assuitable for use as a “lipophilic fluid” in accordance with the presentinvention. However, if two or more separate layers are formed in allthree vials, then the amount of nonaqueous fluid dissolved in the oilphase will need to be further determined before rejecting or acceptingthe nonaqueous fluid as qualified.

In such a case, with a syringe, carefully extract a 200-microlitersample from each layer in each vial. The syringe-extracted layer samplesare placed in GC auto sampler vials and subjected to conventional GCanalysis after determining the retention time of calibration samples ofeach of the three models soils and the fluid being tested. If more than1% of the test fluid by GC, preferably greater, is found to be presentin any one of the layers which consists of the oleic acid, canola oil orsqualene layer, then the test fluid is also qualified for use as alipophilic fluid. If needed, the method can be further calibrated usingheptacosafluorotributylamine, i.e., Fluorinert FC-43 (fail) andcyclopentasiloxane (pass). A suitable GC is a Hewlett Packard GasChromatograph HP5890 Series II equipped with a split/splitless injectorand FID. A suitable column used in determining the amount of lipophilicfluid present is a J&W Scientific capillary column DB-1HT, 30 meter,0.25 mm id, 0.1 um film thickness cat# 1221131. The GC is suitablyoperated under the following conditions:

Carrier Gas: Hydrogen

Column Head Pressure: 9 psi

Flows: Column Flow @˜1.5 ml/min.

-   -   Split Vent @˜250-500 ml/min.    -   Septum Purge @ 1 ml/min.

Injection: HP 7673 Autosampler, 10 ul syringe, 1 ul injection

Injector Temperature: 350° C.

Detector Temperature: 380° C.

Oven Temperature Program: initial 60° C. hold 1 min.

-   -   rate 25° C./min.    -   final 380° C. hold 30 min.

Preferred lipophilic fluids suitable for use herein can further bequalified for use on the basis of having an excellent garment careprofile. Garment care profile testing is well known in the art andinvolves testing a fluid to be qualified using a wide range of garmentor fabric article components, including fabrics, threads and elasticsused in seams, etc., and a range of buttons. Preferred lipophilic fluidsfor use herein have an excellent garment care profile, for example theyhave a good shrinkage and/or fabric puckering profile and do notappreciably damage plastic buttons. Certain materials which in sebumremoval qualify for use as lipophilic fluids, for example ethyl lactate,can be quite objectionable in their tendency to dissolve buttons, and ifsuch a material is to be used in the compositions of the presentinvention, it will be formulated with water and/or other solvents suchthat the overall mix is not substantially damaging to buttons. Otherlipophilic fluids, D5, for example, meet the garment care requirementsquite admirably. Some suitable lipophilic fluids may be found in grantedU.S. Pat. Nos. 5,865,852; 5,942,007; 6,042,617; 6,042,618; 6,056,789;6,059,845; and 6,063,135, which are incorporated herein by reference.

Lipophilic fluids can include linear and cyclic polysiloxanes,hydrocarbons and chlorinated hydrocarbons, with the exception of PERCwhich is explicitly not covered by the lipophilic fluid definition asused herein. (Specifically call out DF2000 and PERC). More preferred arethe linear and cyclic polysiloxanes and hydrocarbons of the glycolether, acetate ester, lactate ester families. Preferred lipophilicfluids include cyclic siloxanes having a boiling point at 760 mm Hg. ofbelow about 250° C. Specifically preferred cyclic siloxanes for use inthis invention are octamethylcyclotetrasiloxane,decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane.Preferably, the cyclic siloxane comprises decamethylcyclopentasiloxane(D5, pentamer) and is substantially free of octamethylcyclotetrasiloxane(tetramer) and dodecamethylcyclohexasiloxane (hexamer).

However, it should be understood that useful cyclic siloxane mixturesmight contain, in addition to the preferred cyclic siloxanes, minoramounts of other cyclic siloxanes including octamethylcyclotetrasiloxaneand hexamethylcyclotrisiloxane or higher cyclics such astetradecamethylcycloheptasiloxane. Generally the amount of these othercyclic siloxanes in useful cyclic siloxane mixtures will be less thanabout 10 percent based on the total weight of the mixture. The industrystandard for cyclic siloxane mixtures is that such mixtures compriseless than about 1% by weight of the mixture ofoctamethylcyclotetrasiloxane.

Accordingly, the lipophilic fluid of the present invention preferablycomprises more than about 50%, more preferably more than about 75%, evenmore preferably at least about 90%, most preferably at least about 95%by weight of the lipophilic fluid of decamethylcyclopentasiloxane.Alternatively, the lipophilic fluid may comprise siloxanes which are amixture of cyclic siloxanes having more than about 50%, preferably morethan about 75%, more preferably at least about 90%, most preferably atleast about 95% up to about 100% by weight of the mixture ofdecamethylcyclopentasiloxane and less than about 10%, preferably lessthan about 5%, more preferably less than about 2%, even more preferablyless than about 1%, most preferably less than about 0.5% to about 0% byweight of the mixture of octamethylcyclotetrasiloxane and/ordodecamethylcyclohexasiloxane.

The level of lipophilic fluid, when present in the lipophilic fluidbased fabric treating compositions according to the present invention,is preferably from about 70% to about 99.99%, more preferably from about90% to about 99.9%, and even more preferably from about 95% to about99.8% by weight of the lipophilic fluid based fabric treatingcomposition.

Drying Time Reduction

The present invention is directed to a method to reduce the timerequired to dry fabrics that have been cleaned or treated with alipophilic fluid. The present invention is also directed to a systemcapable of performing any of methods described hereinafter. The rinseliquor may be neat lipophilic fluid or lipophilic fluid with additivesfor finishing, faster drying, and treatment. As discussed before, theinvention is to heat fabrics contacted with a lipophilic fluid to atemperature above ambient temperature by utilizing at least one of threesteps or a combination of the steps.

One possible step is to blow a gas, preferably a gas heated totemperatures above ambient, onto the fabrics while spraying the liquorused to rinse the fabrics and tumbling the fabrics. The essence of thisstep is to preheat the fabrics and the rinse liquor prior to thebeginning of fabric drying in order to save this preheat time during thedrying cycle. Drycleaners do not typically preheat the rinse liquor orclothes since it provides little, if any, cleaning benefit. Further,drycleaners are not typically concerned with drying time falling intothe range of drying time expected in the home. Drycleaners alsotypically use solvents with lower boiling points or can exceed flashpoint temperatures during drying since most of their equipment operatesat reduced oxygen levels (less than about 8% O₂ in air) during dryingwhich reduces any flash or fire risk. It is important to perform thisstep prior to extracting the rinse liquor (spin cycle) or there will beno drying time saved by utilizing the step.

Another possible step is pre-heating the rinse liquor prior to applyingit to the fabrics. Again, drycleaners do not typically preheat rinseliquors prior to application for the same reasons outlined above. Thisstep is similar to the step above except that the rinse liquor is heatedseparately from the fabrics and the fabrics themselves are not heateduntil the warm rinse liquor contacts the fabrics.

The last of the three inventive steps is exposing the fabrics to anelectromagnetic energy source while spraying rinse liquor onto andtumbling the fabrics but prior to extracting the rinse liquor. Theelectromagnetic energy source can be selected from at least one ofinfrared source, microwave source, and radio frequency source. This stepis essentially the same as the first outlined above; however, ratherthan use a heated gas, the drying energy is derived from anelectromagnetic source. Electromagnetic dryers are commerciallyavailable from companies including Microdry Corporation in Kentucky andRadio Frequency Incorporated in Massachusetts.

An optional step in addition to at least one of those outlined abovecould be to expose the fabrics to a co-solvent having a higher vaporpressure than the lipophilic fluid and/or rinse liquor while still beingmiscible therewith. The high vapor pressure co-solvent may be added tothe lipophilic fluid prior to contacting the fabric articles with thelipophilic fluid. The co-solvent would preferably have a vapor pressurethat is at least about 3 mm Hg at 20° C. It is also preferred that theco-solvent is selected from methylol, ethylol, butylol, and mixtures ofthese co-solvents. It is also preferable that the co-solvent benon-flammable since it will be exposed to heat and the drier andparticularly since the invention may be utilized in the home. Otherpreferred co-solvents are the hydrofluoroethers and the most preferredamong them is methyl nonafluoroisobutyl ether.

Gases suitable for the present invention are preferably selected fromair, nitrogen, steam, and combinations thereof. Further, it is preferredthat the gas flows onto the fabrics and rinse liquor at a rate of 40ft³/min to 250 ft³/min, preferably between 80 ft³/min and 150 ft³/min.It is also preferred that the gas be heated to at least about 10 degreesabove ambient temperature.

It is also preferred that the methods of the present invention occur ina laundering apparatus that has at least one fabric spin velocity and atleast one fabric spin time. It is preferred that the fabric spinvelocity is at or above about 200 G, more preferably at or above about300 G, even more preferably at or above about 400 G. Particularlypreferred are fabric spin velocities at or above 400 G and fabric spintimes at or above about 30 seconds.

Drying the fabrics under vacuum can also help reduce the drying time bylowering the boiling points of the lipophilic fluid or rinse liquor usedduring the wash cycle. Therefore, it is an optional additional step toexpose the fabrics to less than about 1 atm of pressure during drying.

As stated above, the rinse liquor can contain a lipophilic fluid.Preferred lipophilic fluids for use with the present invention includelinear or cyclic siloxanes with the cyclic being the most preferredbetween them. Decamethylcyclopentasiloxane is a particularly preferredcyclic siloxane. These and other suitable lipophilic fluids have beendescribed in detail above. The rinse liquor can also contain finishingor treatment constituents selected from bleaches, emulsifiers, fabricsofteners, perfumes, antibacterial agents, antistatic agents,brighteners, dye fixatives, dye abrasion inhibitors, anti-crockingagents, wrinkle reduction agents, wrinkle resistance agents, soilrelease polymers, sunscreen agents, anti-fade agents, waterproofingagents, stainproofing agents, soil repellency agents, and mixturesthereof. These and other suitable treatment aids have also beendiscussed above.

It will be understood that the present invention may be combined withfabric treatments. For example, prior to cleaning and drying, the fabricarticles may be subjected to the particulate removal method described inco-pending application Ser. No. 60/191,965, to Noyes et al., filed Mar.24, 2000.

The present invention may be used in a service, such as a dry cleaningservice, diaper service, uniform cleaning service, or commercialbusiness, such as a laundromat, dry cleaner, linen service which is partof a hotel, restaurant, convention center, airport, cruise ship, portfacility, casino, or may be used in the home.

The present invention may also be performed in an apparatus having a“contra-rotating” drum. A contra-rotating drum is a two-piece split drumwherein each half of the drum is capable of rotation in a directionopposite the other half of the drum simultaneously. The contra-rotatingmovement is an effective mechanism for randomly rearranging the fabricarticles' positions within the drum. These apparatus are commerciallyavailable from companies such as Dyson.

The present invention may also be performed in an apparatus capable of“dual mode” functions. A “dual mode” apparatus is one capable of bothwashing and drying fabrics within the same drum. These apparatus arewidely available, especially in Europe.

The present invention may be performed in an apparatus that is amodified existing apparatus and is retrofitted in such a manner as toconduct the process of the present invention in addition to relatedprocesses.

Finally, the present invention may also be performed in an apparatus,which is not a modified existing apparatus but is one specifically builtin such a manner so as to conduct the process of the present invention.This would include all the associated plumbing, such as connection to achemical and/or gas supply, and sewerage for waste fluids.

An apparatus used in the processes of the present invention willtypically contain some type of control system. These include electricalsystems, such as, the so-called smart control systems, as well as moretraditional electromechanical systems. The control systems could enablethe user to select the size of the fabric load to be dried, the extentof drying, and/or the time for the drying cycle cycle. Alternatively,the user could use pre-set drying cycles, or the apparatus could controlthe length of the drying cycle, based on any number of ascertainableparameters including, but not limited to, the lipophilic fluid vaporcontent of the drum. This would be especially true for electricalcontrol systems.

In the case of electrical control systems, one option is to make thecontrol device a so-called “smart device”. This could mean including,but not limited to, self diagnostic system, load type and cycleselection, linking the machine to the Internet and allowing for theconsumer to start the apparatus remotely, be informed when the apparatushas treated and dried a fabric article, or for the supplier to remotelydiagnose problems if the apparatus should break down. Furthermore, ifthe apparatus of the present invention is only a part of a cleaningsystem, the so called “smart system” could be communicating with theother cleaning devices which would be used to complete the remainder ofthe cleaning process, such as a washing machine, and a dryer.

1. A method for reducing the drying time of lipophilic fluid-containingfabric articles comprising the steps of: (a) treating fabric articleswith a lipophilic fluid thereby producing lipophilic fluid-containingfabric articles, the lipophilic fluid is a liquid at ambient temperatureand pressure; (b) exposing the lipophilic fluid-containing fabricarticles to a co-solvent having a vapor pressure of at least about 3 mmHg at 20° C.; (c) subjecting the lipophilic fluid-containing fabricarticles to heat.
 2. The method according to claim 1 wherein theco-solvent is a hydrofluoroether.
 3. The method according to claim 1wherein the co-solvent is selected from the group consisting ofmethylol, ethylol, butylol, and mixtures thereof.
 4. The methodaccording to claim 1 wherein the co-solvent is miscible in thelipophilic fluid
 5. The method according to claim 1 wherein thelipophilic fluid is selected from the group consisting of linear orcyclic siloxanes, perfluorinated amines, C6 or higher diols, polyolpolyesters, glycol ethers, and mixtures thereof.
 6. The method accordingto claim 5 wherein the lipophilic fluid comprises a cyclic siloxane. 7.The method according to claim 5 wherein the lipophilic fluid comprisesdecamethylcyclopentasiloxane in an amount of more than about 50% byweight of the lipophilic fluid.
 8. The method according to claim 1wherein the co-solvent is added to the lipophilic fluid prior tocontacting the fabric articles with the lipophilic fluid.
 9. The methodaccording to claim 1 wherein the method further comprises heating thelipophilic fluid to above ambient temperature.
 10. The method accordingto claim 1 wherein step (c) comprises blowing heated gas onto thelipophilic fluid-containing fabric articles.
 11. The method according toclaim 10 wherein the gas is selected from the group consisting of air,nitrogen, steam, and combinations thereof.
 12. The method according toclaim 10 wherein the gas blows onto the fabric articles at a rate of 40ft³/min to 250 ft³/min.
 13. The method according to claim 1 wherein step(c) comprises exposing the lipophilic fluid-containing fabric articlesto electromagnetic energy.
 14. The method according to claim 1 whereinstep (c) comprises contacting the lipophilic fluid-containing fabricarticles with a heated rinse liquor.
 15. The method according to claim14 wherein the rinse liquor comprises a lipophilic fluid.
 16. The methodaccording to claim 14 wherein the rinse liquor comprises an adjunctselected from the group consisting of bleaches, emulsifiers, fabricsofteners, perfumes, antibacterial agents, antistatic agents,brighteners, dye fixatives, dye abrasion inhibitors, anti-crockingagents, wrinkle reduction agents, wrinkle resistance agents, soilrelease polymers, sunscreen agents, anti-fade agents, waterproofingagents, stainproofing agents, soil repellency agents, and mixturesthereof.
 17. The method according to claim 1 wherein the method furthercomprises a step of subjecting the lipophilic fluid-containing fabricarticles to a vacuum pressure of less than about 1 atm.
 18. The methodaccording to claim 1 wherein the method further comprises a step ofsubjecting the lipophilic fluid-containing fabric articles to a fabricarticle spin velocity of at least about 200 G.
 19. A method for dryinglipophilic fluid-containing fabric articles comprising subjecting thelipophilic fluid-containing fabric articles with a co-solvent and atleast one of the following conditions: (a) heating the lipophilic fluidto above ambient temperature; (b) blowing heated gas onto the lipophilicfluid-containing fabric articles; (c) exposing the lipophilicfluid-containing fabric articles to electromagnetic energy; (d)contacting the lipophilic fluid-containing fabric articles with a heatedrinse liquor; such that the lipophilic fluid-containing fabric articlesare dried.
 20. The method according to claim 19 wherein the co-solventhaving a vapor pressure of at least about 3 mm Hg at 20° C.
 21. Themethod according to claim 19 wherein the lipophilic fluid is a liquid atambient temperature and pressure.
 22. A method for reducing the dryingtime of a lipophilic fluid-containing fabric article comprising thesteps of: a. adding a co-solvent to the lipophilic fluid to form asolvent mixture; b. contacting the fabric article with the solventmixture at a temperature above ambient temperature; and c. removing atleast a portion of the solvent mixture from the fabric article such thatamount of lipophilic fluid contained in the fabric article is less than75% of absorptive capacity of the fabric article.
 23. The methodaccording to claim 22 wherein the co-solvent has a vapor pressure offrom at least about 3 mm Hg at 20° C.
 24. The method according to claim22 wherein the high vapor pressure co-solvent is selected from the groupconsisting essentially of: methyol, ethylol, butylol, hydrofluoroethersand mixtures thereof.
 25. The method according to claim 22 wherein thelipophilic fluid is selected from the group consisting of linear orcyclic siloxanes, perfluorinated amines, C6 or higher diols, polyolpolyesters, glycol ethers, and mixtures thereof.
 26. The methodaccording to claim 22 wherein the lipophilic fluid comprises a cyclicsiloxane.
 27. The method according to claim 22 wherein the lipophilicfluid comprises an adjunct selected from bleaches, emulsifiers, fabricsofteners, perfumes, antibacterial agents, antistatic agents,brighteners, dye fixatives, dye abrasion inhibitors, anti-crockingagents, wrinkle reduction agents, wrinkle resistance agents, soilrelease polymers, sunscreen agents, anti-fade agents, waterproofingagents, stainproofing agents, soil repellency agents, and mixturesthereof.
 28. The method according to claim 22 further comprising one ormore of the following steps: a. subjecting the lipophilicfluid-containing fabric articles to heat; b. subjecting the lipophilicfluid-containing fabric articles to a vacuum; c. subjecting thelipophilic fluid-containing fabric articles to a fabric article spinvelocity of at least about 200 G; d. subjecting the lipophilicfluid-containing fabric articles to electromagnetic energy.